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Control of Eukaryotic Gene Transcription
Teachable UnitGene Expression Team
NANSI 2013, University of MinnesotaParticipants: Michael Burns, Lucy He, David Kirkpatrick, Bridget Lear,
Tamar Resnick, Turk RhenFacilitators: Judy Ridgway, Sue Wick
Image Source: http://www.garlandscience.com/product/isbn/9780815341291
ContextCourse: the teachable unit is intended for use in an upper level undergraduate Genetics course.
Time frame: the unit is expected to cover 1-2 class periods within a two week series of units on eukaryotic gene expression, approximately 1/3 of the way into the semester.
Student background: students in this course would have previously completed Introductory Biology for majors, which would include essential background such as the central dogma. Macromolecular structure would also be covered in the first 1/3 of this course.
Learning goalsStudents will understand
Outcomes/ objectivesStudents will be able to
• regulation of eukaryotic gene transcription
• explain cis and trans regulators, distinguish between them, and explain their interactions
• recognize and explain examples of transcriptional activation and inhibition
• predict the effects on gene expression resulting from regulatory perturbations
Learning goalsStudents will understand
Outcomes/ objectivesStudents will be able to
• regulation of eukaryotic gene transcription
• that differences in gene expression can lead to different cellular and organismal outcomes
• explain cis and trans regulators, distinguish between them, and explain their interactions
• recognize and explain examples of transcriptional activation and inhibition
• predict the effects on gene expression resulting from regulatory perturbations
• provide, recognize, and explain examples in which differences in gene expression produce different outcomes for the cell/ organism
Learning goalsStudents will understand
Outcomes/ objectivesStudents will be able to
• regulation of eukaryotic gene transcription
• that differences in gene expression can lead to different cellular and organismal outcomes
• how to interpret and analyze data
• explain cis and trans regulators, distinguish between them, and explain their interactions
• recognize and explain examples of transcriptional activation and inhibition
• predict the effects on gene expression resulting from regulatory perturbations
• provide, recognize, and explain examples in which differences in gene expression produce different outcomes for the cell/ organism
• draw logical conclusions from data
Scientific teaching themes: Diversity and Inclusivity
• Students will be provided with a study guide that will– describe learning goals and outcomes – assist students to organize and prioritize material in reading assignment– provide links to videos/animations/multimedia resources – include references for relevant background resources from previous unitsInclusive of differences in background knowledge and learning styles.
• Learning activities will be designed to encourage participation from all students through the use of a variety of small group, paired, and individual activities. Inclusive of differences in learning styles and personality types.
• Multiple forms of assessment will be used. Inclusive of differences in learning styles.
Presentation Plan: incorporation of active learning and assessment tools
Preclass: Students will read chapter, watch animations, and review study guide to familiarize themselves with the material.
Activity 1: Construction of generic transcription unit using a manipulable model. Activity performed in small groups, followed by class discussion and evaluation. Formative assessment (25 minutes)
Activity 2: Extension of model with hypothetical scenarios in which regulatory components are altered. Individuals will answer clicker questions. Small groups will discuss and manipulate models. Individuals will re-answer clicker questions. Formative assessment (20 minutes)
Activity 3 (tidbit): Mini-lecture and case study that explore the relationship between gene regulation and limb development. Small groups will evaluate data and make predictions using the manipulable model, followed by class discussion and evaluation. Formative assessment (25 minutes)
Height
Phenotypic Variation Within Species
Appendage length
Phenotypic Variation Within Species
Source: http://www.sxc.hu/photo/1330423
Phenotypic Variation Among Species
Source: http://www.bio.miami.edu/dana/160/160S11_3.html
What regulates appendage length?
Prx1, a gene involved in limb length
• “Gene” refers to coding sequence and flanking regulatory sequence
• Prx1 - Paired related homeobox 1
• To understand Prx1 function, scientists compared mouse and bat limb development
Cretekos CJ, Wang Y, Green ED, et al., Genes Dev. 2008 Jan 15;22(2):141-51.
Bats have longer forelimbs relative to body size than mice do
Adapted from Cretekos CJ, Wang Y, Green ED, et al., Genes Dev. 2008 Jan 15;22(2):141-51.
Bats have higher Prx1 expression in the forelimb than do mice
Prx1 mRNAExpression
Bat
Mouse
Adapted from Cretekos CJ, Wang Y, Green ED, et al., Genes Dev. 2008 Jan 15;22(2):141-51.
Wild-type Mutant
Adapted from Cretekos CJ, Wang Y, Green ED, et al., Genes Dev. 2008 Jan 15;22(2):141-51.
What changes in Prx1 might cause this difference?
• Manipulate your models
• Come up with as many different hypotheses as you can
Wild type Prx1-coding sequence deletion
Adapted from Cretekos CJ, Wang Y, Green ED, et al., Genes Dev. 2008 Jan 15;22(2):141-51.
Do Prx1 regulatory elements contribute to interspecies variation?
• Scientists replaced mouse Prx1 regulatory sequence with bat Prx1 regulatory sequence• Do this with your model.
• Use your model to predict the effect on mRNA and protein expression
• Draw your hypothetical mouse
?
Wild type Prx1-delete Bat regulatory region
Adapted from Cretekos CJ, Wang Y, Green ED, et al., Genes Dev. 2008 Jan 15;22(2):141-51.
ShortenedLimb
NormalLimb
ElongatedLimb
FunctionalWing
Which would you predict?
A B CD
Adapted from Cretekos CJ, Wang Y, Green ED, et al., Genes Dev. 2008 Jan 15;22(2):141-51.
Wild type Prx1-deleteBat regulatory
region
Adapted from Cretekos CJ, Wang Y, Green ED, et al., Genes Dev. 2008 Jan 15;22(2):141-51.
Take-Home Question
• Why is there only a small change in mouse limb length with the bat enhancer, considering that bats have much longer forelimbs?
• Give an explanation in terms of gene expression (150 words max)
Summary/ debriefing• explain cis and trans regulators, distinguish between
them, and explain their interactions
• recognize and explain examples of transcriptional activation and inhibition
• predict the effects on gene expression resulting from regulatory perturbations
• provide, recognize, and explain examples in which differences in gene expression produce different outcomes for the cell/ organism.
• draw logical conclusions from data
Summative Assessment
• Potential mechanisms– Exam questions -new example– Part of term paper would involve transcriptional
regulation– Part of poster would involve transcriptional
regulation
Acknowledgements
• Sue Wick, University of Minnesota • Judy Ridgway, The Ohio State University • NANSI organizers
